Adequate evaluation of treatment outcomes is the cornerstone of evidence-based medicine. In most cases, clinicians focus on improvement in psychiatric symptoms to evaluate whether a patient is responding effectively to treatment [1]. In the same vein, most gold-standard instruments that support clinicians work measure psychiatric symptoms, quantifying reduction in severity of symptoms as the indication for clinical improvement [2]. However, our goal, ultimately, is to improve patients’ sense of well-being and overall functioning, making symptom reduction an important yet not exclusive therapeutic goal. Therefore, there is a growing awareness to include measures of quality of life (QoL) in assessing course of illness and response to treatment [3].

In this issue, Jensen et al. [4] investigates QoL in children with Obsessive Compulsive Disorder (OCD), who received 14–24 weeks of manualized Cognitive-Behavioral Therapy (CBT) or a combined treatment of CBT + Specific Serotonin Reuptake Inhibitors. They were followed for 3 years, and the authors included QoL measures in their longitudinal follow-up. The authors identified three groups of children in terms of the clinical course of OCD: acute-sustainable (patients who improved following treatment and sustained low levels of symptom severity throughout follow-up), slow-continued (patients whose immediate response to treatment was mild but improved significantly following further treatment and throughout follow-up) and limited responders (patients who improved mildly following treatment, and had no further improvement during follow-up). The authors found that reduction in symptoms and improvement in QoL only moderately correlated in all three groups. Both the acute-sustainable and the slow-continued groups had similar robust symptom reduction at the 3-year follow-up. Yet interestingly, the group of slow-continued responders did not reach norm-level QoL according to child-reports, despite symptom reduction, as opposed to the acute-sustainable group. In addition, for the slow-continued and the limited responders groups, there was a discrepancy between parent- and child- reports regarding improvement in QoL immediately after treatment, with parents in both groups reporting small but significant improvement while their children reported no improvement at all.

Quality of life is an important measure for treatment outcome, and is pertinent not only in psychiatry but in other medical fields as well [3, 5, 6, 7], where it is defined as health-related QoL, i.e., the ways in which QoL is affected by a medical condition [8]. During the past 3 decades, there is an increasing awareness among physicians to the importance of caring for patients’ QoL [6, 7]. Quality of life has been conceptualized in many ways, but there is a general agreement that it refers to the individual’s subjective perception of well-being and everyday functioning in multiple areas, including physical, emotional, and social functioning [3]. In children with psychiatric disorders, factors that affect QoL include intrapersonal factors such as low self-esteem, interpersonal factors like poor social skills, poor family functioning, and comorbidity with a physical disease [9].

Of note that not all children with psychiatric disorders are reporting lower QoL than children without psychiatric morbidity. In a large-scale community survey of over 45,000 children from 880 schools across the UK, the proportion of children with psychiatric disorder reporting having high QoL was only slightly lower than that of children without psychiatric disorders, ~ 12% vs. 16.5%, respectively [10].

Similarly to the findings of Jensen et al. [4], in most cases, psychiatric symptom reduction is somewhat correlated with an improvement in overall QoL [3,4,5, 11]. However, in some cases there is a gap between these outcomes, which can go in both directions. For example, in a longitudinal study that investigated QoL among a sample of pediatric outpatients with psychiatric disorders, in 17.5% of patients psychiatric symptoms improved while their QoL was unchanged or even deteriorated. Conversely, 11.1% of patients improved in QoL without symptom reduction [11]. Jensen et al. also demonstrate some gaps between symptom severity and QoL, and show that even though symptom severity of the acute-sustainable and slow-continued responders was aligned at 3-year follow-up, slow-continued responders presented lower scores in some domains of QoL (especially for child ratings), including the disorder domain which represents individuals’ subjective experience of their disorder [4]. This highlights the gap between clinicians’ rating of symptom severity and the more subjective experience of QoL, and emphasizes the need to address QoL to identify patients who require further treatment despite relatively low symptomatology.

Quality of life is significantly compromised by all psychiatric disorders [5]. The significance of QoL in psychiatry is even recognized by the Diagnostic and Statistical Manual of Mental Disorders, where functional impairment is required to qualify for any diagnosis, meaning that a diagnosis cannot be given unless symptoms cause a significant distress or lead to functional impairment in areas like social or occupational functioning [12]. It has also been found that patients’ impairment is proportional to their number of psychiatric diagnoses [9, 10, 13].

Jensen et al. [4] found some additional incongruities between child and parent reports of QoL. Specifically, lower parent-reported QoL was associated with higher externalizing symptoms, while lower child-reported QoL was associated with higher internalizing symptoms. Disagreement between child- and parent-report is common when assessing QoL [3, 13, 14]. In most cases, agreement is higher when problems are observable, for example when a physical illness or disability is present. Conversely, agreement is lower for unobservable phenomena, such as internalizing symptoms, where children tend to report lower QoL than their parents [14]. Awareness of these gaps between child and parent reports on QoL is important for clinicians who aim to utilize QoL measures in their clinical work.

As presented in Table 1, there are several commonly used measures of QoL in children, with good psychometrics in terms of internal consistency, age-appropriateness, self- vs. external-report validity and cross-cultural appropriateness, including the Pediatric Quality of Life (PedsQL) Inventory, KINDL-R Revised Children’s Quality of Life Questionnaire, DISABKIDS Quality of Life Inventory, Child Health and Illness Profile, the Child Health Questionnaire and the KIDSCREEN Quality of Life Questionnaire [15]. These instruments generally measure similar dimensions: physical, emotional/psychological, social and familial functioning. Yet, they vary in several other aspects. Some questionnaires offer disease-specific modules alongside the generic version, that are designated for children who suffer from a certain physical illness (e.g., Obesity, Asthma, Diabetes, Cancer and more). The instruments vary in length and psychometric properties, are adapted for different age ranges, have self-report and parent-report versions, some rely on interviews and others on self-report questionnaires. While all of the reviewed questionnaires are available in English, there is a variation in their availability in other languages, although all of them were translated to multiple languages (see Table 1) [15]. A review of studies that measured QoL found that PedsQL is the most frequently used instrument in children with psychiatric disorders [13].

Table 1 Properties of different Quality of Life instruments
Full size table

In conclusion, measuring QoL is quite simple, as a number of well-validated tools are available and adapted for children and parents [3, 15]. Integrating QoL into psychiatric assessments and clinical studies is important for providing a more holistic picture of our patients, and can improve our ability to identify children who are coping with low well-being despite improvement in psychiatric symptoms.